Sanitary drain valve design

ABSTRACT

A valve for sampling a process from a tank or conduit includes an internal cavity in communication with at least one inlet and an outlet. A valve actuating rod includes a sealing tip attached to one end thereof. The valve actuating rod is movable to open and close the inlet to the internal cavity. Furthermore, a seal is provided to isolate the valve actuating rod and the outside environment from the process. The seal is formed on the process side of the bottom wall of the internal cavity in order to ensure that the process material, cleaning material, steam, etc. drains completely out of the internal cavity of the valve.

This application is a divisional of application Ser. No. 09/801,783,filed on Mar. 9, 2001, now U.S. Pat. No. 6,491,283 the entire contentsof which are hereby incorporated by reference and for which priority isclaimed under 35 U.S.C. §120; and this application claims priority ofapplication Ser. No. 60/187,996 filed in U.S.A. on Mar. 9, 2000 under 35U.S.C. §119.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to an improved sanitary valve design.In particular, the present invention is directed to a sanitary valvedesign that allows for free-drainage of process and sterilizing andcleaning materials.

2. Description of Background Art

There have been many incidents where sanitary processes have failed,resulting in loss of product. In some cases, harm to consumers occurs.In many instances the specific nature of the source of contaminationremains unidentified. In many other instances; however, the source ofcontamination has been traced back to drain valves, which have not beenproperly cleaned, and in many cases where procedures specify it,sterilized between production runs.

Failures have not been limited to valve designs traditionally viewed asbeing problematic when used in sanitary applications (tulip and kettlevalves, plug and ball valves, e.g.) but, rather, extend to include weirand radial diaphragm valve designs which are currently consideredstate-of-the-art designs particularly suited for sanitary processingapplications.

The causes for these failures, almost without exception, relate tomaterial accumulation in low, undrainable pooling areas and in tightcrevice areas, particularly those associated with moving parts such assliding or rotating O-ring seals. Deep, tight joints, particularlyaround moving parts, are primary sites for material to accumulate andare ideal safe havens for microbial proliferation. These sites canbecome tightly packed with highly nutricious process materials, whichprovide insulation and protection from cleaning and sterilizing agents,allowing significant microbial populations to develop over time.Deposits of tightly adhering organic and inorganic material resist theeffects of caustic and acidic cleaning solutions, mechanical shear fromagitation and high rates of circulation and from the effects of steamsterilization. Large deposits may develop in valves over time, aconsequence of the selection of valves emphasizing design robustness andmechanical reliability over in-situ process cleanability andsterilizability. Cleaning and sterilizing followed by the initiation ofprocess production may cause large deposits or accumulations to softenand slough or break off, getting blended into downstream processmaterials, representing significant contamination to the process. Theselarge deposits are of particular concern because they representcontamination threats large enough to significantly affect productquality and process outcome even for processes traditionally consideredvery robust, such as some food, beverage and chemical production.

If gone undetected, product exposure can, in some cases, be harmful oreven fatal. For this reason, regulators as well as the regulatedindustry have begun to look more closely at the source of the problemand search for ways to minimize it. An important part of this effort hasbeen to implement more active preventative maintenance and inspectionprograms for valves. At some point, however, increasing humanintervention becomes impractical and cost-prohibitive. Another part ofthe effort has been to re-examine the root cause of the problem.Specifically, the performance of current valve designs in sanitaryprocess applications where valve maintenance efforts between productionruns has been practically limited to in-situ cleaning, rinsing and steamsterilization.

As it turns out, process failures, although strongly skewed towardprocesses which have included valve designs which are dependent onsliding or rotating O-ring seals (i.e. ball valves, plug valves, tulipvalves and kettle valves, have not been limited to these designs. Aoki,U.S. Pat. No. 3,949,963 and Lerman et. al., U.S. Pat. No. 4,822,570disclose some typical examples of valve designs which may experienceprocess failures. Even though many of the new sanitary processes beingimplemented include state-of-the-art weir diaphragm and radial diaphragmdrain valve designs, failures still persist in these processes, albeitat a decreased rate. Typical examples of the above valve designs areButler et. al., U.S. Pat. No. 5,277,401, Hoobyar, U.S. Pat. No.5,152,500 and Ladisch, U.S. Pat. No. 4,836,236.

Diaphragm valves, with flexing diaphragms that allow valve actuationwhile isolating the process from moving valve parts and the surroundingoutside environment, generally include less crevice areas and havesmooth surfaces, all of which make them the best candidates availablefor use in CIP (clean-in-place) and SIP (steam sterilize-in-place)sanitary process applications. Of the other, more traditional valvedesigns, tulip and kettle valves are most frequently found in sanitaryprocess applications. These valves are relatively inexpensive to installand maintain and are simple and mechanically reliable. Furthermore, eventhough they have more crevices as compared to diaphragm valves, it hadbeen thought that their benefits were greater than their weaknesses andtheir weaknesses were not so serious as to restrict their use inprocesses requiring CIP and SIP steps before each batch, particularly inthe more robust, food, beverage and chemical processing applications.

Inspection of valves commercially available today and of the backgroundart reveal certain features common, not only to those drain valvesmaking use of O-ring seals but also to both types of diaphragm drainvalves. In particular, the seals formed between the valve body and thediaphragm or O-ring are made with the second, lower side of the bottomwall of the valve body internal cavity. As a result, the thickness ofthe bottom wall between the first (process) and second (non-process)sides form the wall of a well which is not possible to drain and servesto entrap and shelter process material, cleaning agents, rinse water andsteam condensate. In some diaphragm designs, this well, though verylarge in diameter and, therefore, capable of harboring a large volume,relatively speaking, most areas can be washed clean except for the areaimmediately adjacent to the well wall. The problem associated withvalves equipped with O-ring seals is, generally speaking, just theopposite. The wells above the seals tend to be very narrow because ofthe need for tight tolerances and a relatively close fit between thevalve operating rod and O-ring/O-ring groove combination. Although thevolume of the well tends to be much less, effective access for properCIP and SIP procedure execution is not consistently possible.

Another problem area of valves associated with the design of bottom sealdevices is their general tendency to have at least partially flat bottomwalls to the valve internal cavity. While these walls may make thesevalves easier to fabricate, flat surfaces do not contribute to achievingpositive drainage of materials from within the valve. Standing fluids,in many instances, can be as large of a threat of contamination asentrapped material, sometimes more because of the presence of largeamounts of water, an important ingredient for microbial proliferation.

While the devices mentioned in this discussion may have certainweaknesses when used as drain valves or similar applications in sanitaryprocesses, they may be perfectly adapted for other applications. It isthe author's intent, however, to describe a valve design which includesseveral novel features which are flexible in concept and lend themselvesto the improvement of more traditional drain valve designs. Among theseare the elimination of the seal well in the bottom wall of the valveinternal cavity which can be combined with the introduction of a bottomsurface sloped toward the drain opening so that the bottom wall of thevalve will actively urge process material, cleaning solutions, rinsesand steam condensate to flow down and out of the valve. Other featuresinclude the option of rearranging secondary inlets and the drain outletso as to encourage a swirling, scouring action of materials flowingthrough the valve so that more effective CIP and SIP results can beachieved. The new design will be illustrated in both diaphragm andO-ring type seal designs.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved generalvalve design having good characteristics of process isolation andin-situ cleanability in many orientations as well as providing specificimprovements in cleanability and drainability performance capabilitiesover the background art when used in conduit or tank bottom valveapplications.

Another benefit of the present invention is an improved, free-draining,cleaner sealing arrangement for tulip, kettle and other O-ring-basedseal designs, it also being possible to clean and sterilize the sealingarrangement from the back, non-process side independently from theprocess side on a descript or continuous basis, even while the valve isbeing operated.

A further object of the present invention is to provide a valve that canbe mounted directly on the bottom of a tank, and, in the diaphragmconfiguration, can provide absolute isolation of the process from thevalve components and the outside surrounding environment. Furthermore,in the case of o-ring designs, the present invention can provide a highdegree of isolation of the process from the valve components and theoutside surrounding environment.

A benefit of the device of the present invention is that it provides asmooth, crevice free flow path, which will permit very highly effectivedrainage of process material from a tank or conduit.

Another object of the present invention is to provide a design that canbe flush-mounted, thereby eliminating the formation of dead zones at theinlet into the valve.

Yet another object of the present invention is to provide a valve designwhere process material, cleaning solutions, rinse water and steamcondensate drains down and away from the seal formed between the valvebody and the sealing body (diaphragm or O-ring), eliminating theundrainable well or sump area that occurs in the prior art wherematerial collects and is difficult to remove.

Another object of the present invention is to provide an internal valvebody design with a second inlet positioned in the same plane or abovethe outlet and directed so that flow from the second inlet flows into,around and out of the internal cavity of the valve in a circular orspiral path so as to provide improved CIP and SIP performance.

Still another object of the present invention is to provide a designthat can be actuated manually or automatically and which can be openedpartially or fully, thereby allowing the valve to be used to regulateflow.

A further benefit of the valve design concept of the present inventionis that it can be employed in many design forms all of which may providediaphragm isolation in combination with drainable seals and internalvalve cavities.

Yet another object of the present invention is a valve body design thatcan be fabricated as a single piece

Still another benefit of the present invention is that the same valvebody may be used in many different installation configurations, becausethe connection flange may be constructed as a separate piece from thevalve body, allowing it to be changed to fit a clamp or bolt patternalready installed on the vessel or conduit.

An additional benefit of the present invention is that the diaphragmarrangement valve may be constructed of many types of material so as toimpart flexibility of manufacture and use in a variety of differentmaterial processes.

A further benefit of the valve design concept of the present inventionis that it illustrates how the diaphragm may include single or multiplesections, and guidance on how those may be incorporated into sealingarrangements in the valve in order to provide a greater range of motionfor the sealing tip of the valve even when the diaphragm membrane mayexhibit greater or lesser degrees of rigidity, flexibility orelasticity.

Another benefit of the valve of the present invention is that it may berotated 360 degrees so as to provide greater installation versatility.

Yet another purpose of the present invention is to provide a simple,economic design that may easily be disassembled for maintenancepurposes.

Another object of the present invention is to provide a design that canbe used to great effect over other prior designs in installations andapplications other than tank or conduit drain applications and wheresuperior clean-in-place and sterilize-in-place as well as drainabilitycharacteristics will be demonstrated.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a cross-section of a 1-piece “Mushroom” diaphragm valve inclosed position, with a second inlet feeding to the internal cavitythrough the valve body side wall, above the drain opening;

FIG. 2 is a cross-section of a 1-piece “Mushroom” diaphragm valve in anopened position, with a second inlet feeding into the internal cavitythrough the cover plate from a radial position;

FIG. 3 is a perspective view in cross-section of one alternativediaphragm design offering a greater range of motion through theincorporation of a bellows;

FIG. 4 is a cross-section of a 2-piece “Mushroom” diaphragm valve;

FIG. 5 is a close-up cross-section of the 2-layer diaphragm sealingdevice mounted in the cap;

FIGS. 6(a)-6(e) are central cross-sections of examples of otherdiaphragm sealing arrangements;

FIG. 7 is a cross-section of an example of inverted sealing technologyapplied using a diaphragm in a tulip valve configuration;

FIG. 8 is a cross-section of an example of the inverted sealingtechnology applied in an O-ring configuration to a tulip valve designand incorporating CIP/SIP capabilities to the non-process side of theseal as well as the process side; and

FIG. 9 is a cross-section of an example of the inverted sealingtechnology applied in an O-ring configuration to a plunger valve designand incorporating CIP/SIP capabilities to the non-process side of theseal as well as the process side.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In general, the device of the present invention includes a valve bodyequipped with a manual, automated or combination actuator capable ofmoving a sealing tip attached to a valve operating rod reversibly into asealing condition with a valve seat surrounding a first inlet flowpassage into an internal cavity in the valve body. The valve body has atleast one outlet flow passage placed at the bottom of the internal valvebody cavity to receive drainage, the bottom preferably but notnecessarily being cantilevered or otherwise formed so as to assistdrainage down to at least one outlet flow passage. A seal is formedbetween the static valve body and the dynamic valve actuating rod inwhich, whether an O-ring seal or diaphragm seal is used, the interfacebetween the sealing elements is carried out in a face-down configurationso as to create a self-draining sealing interface and to eliminate thepooling that is associated with sump or well areas that occur in theannular space above the face-up seals found in the background art. Onepreferred arrangement of the device includes a second inlet which isplaced near the top of the internal cavity, near the first inlet butspaced radially from it, a bottom outlet placed at the bottom of theinternal cavity, the opening of the second inlet and the opening of theoutlet being diametrically opposed with regard to flow in such a waythat flowable material fed through the second inlet will spiral down andaround, sweeping and scouring the sides of the internal cavity beforeflowing directly into the facing bottom outlet. The device will bedescribed in detail below in some of the various configurations it maybe designed into once the main concept of the present invention isunderstood.

A valve design arrangement will be described which includes a one-pieceflexing diaphragm with a sealing tip which, when actuated by a valveoperating rod, cause the sealing tip of the diaphragm to form areversible process seal with the valve body so as to permit control ofprocess flow through the valve all while maintaining the integrity ofthe process separate from that of the valve and the surrounding outsideenvironment.

FIG. 1 is a center cross-sectional view of one preferred embodiment ofthe device of the present invention, shown in position as a bottom drainvalve. As shown, valve assembly 1 includes a valve body subassembly 2,diaphragm subassembly 3, valve actuator rod subassembly 4 and actuatordevice 5, which, in this case, is a manual actuator. It should be notedthat all of the internal passages of the valve which are in contact withthe process material should be rounded in order to avoid any sharpcorners where the process material, cleaning materials, steam, etc. mayaccumulate. Several of the Figures in the present application illustratesharp corners, although it is preferable that curved corners beincluded.

The valve body subassembly 2 will now be described. The valve bodysubassembly 2 includes a valve body 10 and a cover plate 100 which areconnected together by an attachment device 107. Valve body 10 has aninternal cavity 11 with a bottom wall 12 having an upper first side 85and a lower second side 86, upper first side 85 being exposed to theprocess, lower second side 86 being removed from the process. Internalcavity 11 or valve body 10 is in communication with at least one drainoutlet 30 and at least one first inlet 20. The drain outlet 30 is incommunication with a drain passage opening 31.

The upper surface 102 of cover plate 100 forms a portion of a wall ordrain basin 103 of a tank or conduit (not shown). The lower surface ofcover plate 100 forms a roof 13 of the internal cavity 11.

In the example shown, first inlet 20 is centered at the bottom of drainbasin 103 having a bottom formed by the upper surface 102 of the coverplate 100. A second side of the cover plate 100 forms an uppermost sideor roof 13 of internal cavity 11. The annular surface of roof 13immediately adjacent the first inlet 20 forms an inlet annular sealingsurface 21 with which a seal is reversibly formed when mated with anannular diaphragm sealing tip surface 63 on an actuating cap or sealingtip 83.

It should be noted that FIG. 1 illustrates roof 13 with a conicalprofile that tapers up to the first inlet 20. Although not a necessity,the taper can improve flow through the valve and serve as a guide tocenter the annular diaphragm sealing tip surface 63 onto the matinginlet annular sealing surface 21.

By way of example, cover plate 100 is illustrated with upper flanges 105welded into a wall of a conduit or vessel (not shown). However, coverplate 100 may take many other forms such as, for instance, a sanitaryferrule with an internal diameter the same as the diameter of the firstinlet 20 and to which the valve assembly could be attached.

In addition, cover plate 100 can be attached to the valve body 10 by anattachment device 107 such as a bolt 108 and threads 109 as shown inFIGS. 3 and 4 or, as shown in FIGS. 1 and 2, mating flanged elements.Clamp 113 clamps cover plate flange 101, located above and valvemounting flange 112, located below, together about swivel shoulder 111.Swivel shoulder 111 engages with mounting flange shoulder 114. Whileswivel shoulder 111 would not be necessary in order to be able to swivelthe valve to any position over 360 degrees if the attachment device istwo flanges clamped together as shown in FIG. 1, if; however, theattachment device 107 includes a bolt pattern, the assembly would onlybe able to be rotated to certain positions. A significant benefit ofhaving valve mounting flange 112 as a distinct piece from valve body 10as shown in FIG. 1 is that it will allow one standard body of the valveto be mated with a variety of preexisting bolt and clamp patterns.

When the attachment device 107 is tightened, the upper margin 116 of thevalve body 10 is moved into contact with the bottom of gasket 115 whilethe annular recess 117 of cover plate 100 is moved into contact with thetop of gasket 115, creating a seal between the cover plate 100 and thevalve body 10. For diaphragm change-out and other maintenanceprocedures, valve body 10 and the attached actuator device 5 may bequickly and easily disconnected from cover plate 100 by removing theattachment device 107.

Valve body 10 may have a second inlet 160 entering into internal cavity11 through a second inlet opening 161 in the side wall of valve body 10as shown in FIG. 1. This additional inlet generally would be used tosupply cleaning solutions, rinse water and steam to clean the valvein-situ between uses. Placing the second inlet in a side wall of valvebody 10 as shown in FIG. 1 may be simpler to do than in many otherplaces on the valve, but the most effective location is likely to benear the top of the internal cavity 11, radially from the diaphragm andoffset to one side, preferably in an orientation that would direct inletflow in a downward spiral pattern with the flow being oriented so as toflow directly into the drain passage opening 31. FIG. 2 illustrates anexample of effective positioning of the second inlet 160. Drain passageopening 31 is shown centrally placed at the bottom of internal cavity11. Drain passage opening 31 might be most effective if it was shiftedto the side so as to capture more fully the second inlet flow.

Drain outlet 30, which is in communication with drain passage opening 31opens into drain passage 32, which, in turn, leads to drain passage exit33. Drain passage exit 33 includes a drain connection device 34 forforming a connection to downstream piping so as to convey the materialdrained through the valve assembly away. By way of example, drainconnection device 34 is shown here as a sanitary clamp connection butcould be any suitable form of connection capable of conveying drainedmaterial. In the preferred embodiment shown, bottom wall 12 is showndeclining to drain passage opening 31. Although not a necessity, thisarrangement would generally be considered a desirable one since theslope of bottom wall 12 and its smooth, uninterrupted transition acrossdrain passage opening 31 into drain passage 32 combined with thedeclining orientation of the drain passage 32 would passively urgematerial from within the valve, thereby acting to keep it clean and freeof potential contaminants. This feature is generally lacking in thebackground art and in equipment available today, the details of whichwill be discussed below.

A primary source of problems occurring in valves used as drain valves insanitary applications relates to the seal arrangement made between thevalve body and the valve operating rod. With valve designs in use today,a seal is formed between a second side of the bottom wall of theinternal cavity with a sealing element, be it an O-ring or diaphragm.Because this seal is formed behind the second side of the bottom wall,the position of this portion is at the lowest point in the internalcavity, below even the opening to the drain outlet. As a consequence,drain valves being used today all tend to collect material in the basinformed about the seal. The thickness of the bottom wall, between thefirst, process side and the second, non-process side, dictates howreadily material can be flushed out of the pooling area about the seal.Even in the best of situations this is still a concern to operators.

It is the purpose of the present invention to provide a new sealingdevice that will eliminate the well or crevice area found at the bottomof valves, thus removing a significant risk factor for processcontamination.

In the place of the bore with a seal face on the second side of thebottom wall 12 of valve body 10 for mating with either an O-ring ordiaphragm found in other valves, the present invention includes acentral raised tubular structure or pedestal 50. Shoulder 43 ofdiaphragm clamp sleeve 40 is inserted up into diaphragm shoulder recess64. A lower portion of diaphragm clamp sleeve 40 is inserted intopedestal central bore 51. Furthermore, the diaphragm clamp sleeve 40includes a central bore 41 through which a valve operating rod 130passes. As diaphragm clamp sleeve 40 is pulled further down intopedestal central bore 51, shoulder 43 pulls a bottom, process-sidesurface or shoulder 68 of diaphragm 60 down and into contact with topannular surface 53 of pedestal 50. As the threads 142 of retainer nut140 are further tightened onto clamp threads 42 of diaphragm clampsleeve 40, the upper face of retainer nut 140 is brought into contactwith a second side 86 of bottom wall 12, causing diaphragm clamp sleeve40 to be pulled further down into pedestal central bore 51 and causingshoulder 43 to compress the shoulder 68 of diaphragm 60 against topannular surface 53 of pedestal 50, forming inverted seal 56 with it.Inverted seal 56 and other seals like it that will be discussed beloware all exposed seals that are easy to clean in-situ and are passivelyself-draining seals that tend to shed process material rather thancollect them. The retainer nut 140 includes retainer nut flats 141 forengaging with a wrench to tighten the retainer nut 140. FIG. 1 depictsupper lip 69 and lower lip 70 on shoulder 68 interlocking with lip 44 onshoulder 43 and raised outer annular lip 52 on top annular surface 53,respectively. These interlocking structures add to the stability of theseals formed but may not be necessary, depending on the physical andchemical process conditions that will be encountered. Also, while themating surfaces of shoulder 68 of diaphragm 60, of top annular surface53 of pedestal 50 and shoulder 43 of diaphragm clamp sleeve are allshown as being generally horizontal, this need not be the case. Whilearrangements that are horizontal or angled so as to promote drainage tothe outside diameter of the pedestal are preferred, arrangements havingan angle down and toward the inside of pedestal 50 can also provide goodresults.

Diaphragm 60 may be formed as a one-piece unit with a threaded tipinsert 81 as shown in FIG. 1. Diaphragm 60 also includes a flexing upperbase shoulder 67, neck 65, and sealing tip 62. The threads 132 on thetip of valve operating rod 130 may be threaded up into threads 87 ininsert 81. In order to assure that valve operating rod 130 does notunscrew from insert 81 during operation, when valve operating rod 130 isinserted through diaphragm clamp sleeve 40, a pin 138 may be insertedpartway through a hole 47 in the wall of diaphragm clamp sleeve 40 sothat it extends into a longitudinal keyway 136 in the side of valveactuating rod 130. Likewise, to keep diaphragm clamp sleeve 40 fromrotating, a longitudinal keyway 45 is fitted with a pin 46 which extendsout into a recess notch 48 cut into the second side 86 of bottom wall12. Pin 46 is fixed in notch 48 by pressure from below by the upper faceof retainer nut 140.

Valve operating rod 130 includes a long neck 121 that fits insidediaphragm neck 65. At the base of long neck 121 is a diaphragm supportshoulder 122 that mates with flexing upper base shoulder 67 of diaphragm60, providing it with support. Just below the diaphragm support shoulder122 is an O-ring 134 and groove 135 that seals between valve operatingrod 130 and the central bore 41 of diaphragm clamp sleeve 40. The lowerbody 123 of valve operating rod 130 terminates in T-cap 137. T-cap 137fits into a T-slot 146 formed in handwheel 144, which is equipped withthreads 145 which mate with opposing bonnet threads 155 formed in bonnet163. The lower portion of handwheel 144 fits into a central bore 165 inhandgrip 156 where it is pinned with a lock-pin 148 inserted in a bore158 extending laterally through the side of handgrip 156 and into asimilar bore 147 in handwheel 144.

Handgrip 156 has a handle sleeve 157 that fits around the outside ofbonnet neck 164 and seals against it with an O-ring and groovecombination 159. In FIG. 1, bonnet 163 has a base plate 151 withalignment lip 154 and bonnet recess 152 and is shown affixed to valvebody 10 by bolts 149 inserted in bolt holes 153 formed in base plate 151and threaded into valve body 10. This method of attachment is simply oneexample of many different ways that could be used to attach the bonnet163 to the valve body 10.

When handgrip 156 is rotated, handwheel 144 is threaded up or down inbonnet 163, pushing and pulling valve operating rod 130 and the attachedsealing tip 62, causing sealing tip 62 of diaphragm 60 to reversiblyseal and unseal the valve.

FIG. 2 depicts the valve in an opened condition. FIG. 2 also shows analternative position of the second inlet 160 which offers benefits withregard to improved cleaning, rinsing and sterilizing over the positiondepicted in FIG. 1. The remaining elements in FIG. 2 are the same asthose in FIG. 1 and have therefore not been further described.

FIG. 3 depicts one alternative diaphragm design offering a greater rangeof motion through the incorporation of a bellows 66 as an integral partof the diaphragm 60, the embodiment of FIG. 3 fails to include thesecond inlet 160 of FIGS. 1 and 2; however, it should be understood thata second inlet 160 may be included, depending on the application. Theremaining elements in FIG. 3 are substantially the same as those inFIGS. 1 and 2 and therefore have not been further described.

FIG. 4 depicts another arrangement of the inverted seal design of thepresent invention in which the diaphragm 60 is annular or frusto-conicaland double-layered. The arrangement shows inner and outer diametersealing arrangements in addition to depicting one method by which a2-layer sealing cap 83 may also be secured over an insert 81. FIG. 4also illustrates another attachment device 107 for connecting valve body10 to cover plate 100, as described previously, wherein a bolt 108 andthreads 109 are used to secure the elements together.

FIG. 5 is a close-up of the sealing device of the valve 1 shown in FIG.4. As can be clearly understood, the sealing cap 83 includes two layers.A first, outer layer 88 and a second, inner layer 89. Furthermore, thediaphragm 60 includes two layers 94 and 95.

Diaphragms used in the food, beverage and pharmaceutical industries areusually made of Buna-N (Butadiene/acrylotonil), EPDM(Ethylene/propylene/diene), Viton (Flurocarbon), Silicon (Medical gradesilicon) or TEFLON (PTFE or Polytetraflouroethylene)

PTFE is frequently used where diaphragm purity or inertness are desired,like with many products that might be injected. The problem with PTFE isthat it is fairly still, more like plastic than rubber and tends to coldflow, meaning that you might tighten it down snugly today but, over timeand under pressure, it will buldge out to the sides and become looseagain. That is why it is pretty common to put some type of layer ofrubber (elastomeric) backing material behind it. That way the rubbermaterial continues to press the Teflon into the mating sealing surfaceeven after it has begun cold-flowing under pressure. Actually, a sealmade with PTFE without backing may stay water tight for a week or amonth but with rubber backing it might continue to hold for years.

It should be noted that the embodiments of the present inventionillustrated in FIGS. 1-3 may also include two layer diaphragms and theembodiment of FIGS. 4 and 5 may be made with one layer of material forthe sealing cap 83 and the diaphragm 60, depending upon the particularapplication of the valve 1.

By way of example, FIGS. 6(a) to 6(e) depict several other methods bywhich inverted sealing arrangements can be made.

FIG. 6(a) illustrates another manner in which the concept of theinverted seal can be applied. The valve in this figure is similar tothat in FIG. 1. The embodiment of FIG. 6(a) differs in that thediaphragm 60 does not include the neck 65 and shoulder 67 as shown inFIG. 1 but, instead, includes only a shoulder 68 with the sealing tip62, supported from underneath by the shoulder 187 of the insert 81,forming a reversible seal with the annular sealing surface 21 about thefirst inlet 20 (see FIG. 1).

A further difference is that the shoulder 68 extends much furtherinward, toward the central axis of the valve actuating rod 130 where itforms a seal with the pedestal 50. As a consequence, the pedestal 50 anddiaphragm clamp sleeve 40 necessary to form the static seal between thebottom process side of the diaphragm 60 and the top process side of thepedestal 50, would probably be narrower than shown in FIG. 1 for thesame size valve. This is because the flexing portion 59 of the diaphragm60 is now formed in the shoulder 68, rather than in the shoulder 67 asin FIG. 1. Also, if the valve were generally of the same dimensions asthe one shown in FIG. 1, the pedestal 50 and the diaphragm clamp sleeve40 would need to be longer in order that a newly positioned sealingsurface 63 of the diaphragm 60 may be brought into contact with thesealing surface 21 about the first inlet 20. Another differenceillustrated in FIG. 6(a) would be the elimination of the shoulder 122between the lower body and the neck 121 of the valve operating rod 130.This structure, designed to support the flexing upper shoulder 67 of thediaphragm 60 from underneath, could be included as a shoulder 49 builtinto the pedestal 50, similar to that seen in FIG. 4.

FIG. 6(a) also depicts other differences from FIG. 1. The shoulder 187of the insert 81 includes an undercut 181 where the diaphragm 60thickness is made greater. This thickness or rib 182 serves to stabilizethe diaphragm 60 and dampening the motion occurring along the shoulder68, inhibiting its transfer through the diaphragm 60 up to the sealingsurface 63 of the diaphragm 60 where it reversibly seals with sealingsurface 21 about the first inlet 20. A further stabilizing diaphragminclusion is the first ring 183 positioned in the diaphragm 60 near theouter rim of the insert 81. Besides serving to dampen the transfer ofmotion caused by the flexing of the shoulder 68, both the rib 182 andthe first ring 183 tend to keep the diaphragm 60 from shifting inposition relative to the insert 81.

FIG. 6(a) also includes a second ring 184 positioned within thediaphragm 60 about the center hole 72 of the diaphragm 60 and adjacentto where the process side of the diaphragm 60 forms a static seal withthe first, upper, process side of the bottom wall 12 of the internalcavity 11. In all of the other depictions of diaphragms provided in thepresent disclosure, the diaphragm 60 has no inclusions and, in order tostabilize the diaphragm 60 where it is desirable to form static sealswith valve elements, lips have 69 and 70 have been shown constructed inthe diaphragm 60 which interlock with opposing lips 44 and 52 in themating valve elements. It is usually more expensive to includeinterlocking combinations. Accordingly, where possible and acceptable,it would be desirable to eliminate these lips, both in the structure ofthe diaphragm 60 and in the valve elements. An alternative approachwhich may sometimes be acceptable and, in some instances preferable, aninternal stabilizing element may be used, here, shown as rings 183 and184. Other approaches include perforated washer insertions, cloth orwire mesh and many more items. If properly stabilized, the lips on boththe diaphragm clamp sleeve 40 and the pedestal 50 could be eliminated,as shown in FIG. 6(a) in any of the embodiments of the presentdisclosure.

Sometimes these inclusions present manufacturing and assemblychallenges. In this case, the diaphragm 60 could be molded around thethreaded insert 81 with the diaphragm clamp sleeve 40 nested up into theannular cutout 185 shown. The rings 183 and 184 could be stabilizedduring the molding process from the insert 81 and the diaphragm clampsleeve 40.

Lastly, the outer margin of the shoulder 68 of the diaphragm in FIG.6(a) comes to a relatively sharp edge, a structure not seen in otherdrawings herein. This is a drip lip 186, designed to encourage materialsrunning down the upper surface of the sealing tip 62 to drip off ratherthan cling to the underside of the diaphragm 60 and flow down over theseal and down the side of the pedestal 50.

FIG. 6(b) is the same as FIG. 6(a) with regard to peripheral structuresof the valve (not shown). FIG. 6(b) is also similar to 6(a) in that theflexing of the diaphragm 60 takes place on the shoulder 68 asillustrated by the flexing portion 59. In FIG. 6(b) is shown retaininginterlocking lip structures 187 and 188 formed in each of the two layersof the diaphragm 60 as well as in the mating valve elements shown. FIG.6(b) includes a double-layered diaphragm 60 as do FIGS. 4, 5, 6(c), 6(d)and 6(e). FIG. 6(b) also depicts a pedestal shoulder 49 (described inthe discussion about FIG. 6(a) above) which is positioned in much closerproximity to the shoulder 68 of the diaphragm 60, more clearlyillustrating how it would provide support from below when the sealingassembly is retracted, as it is shown here; FIG. 6(a) shows the assemblyextended. Another difference between the assemblies shown in FIGS. 6(a)and 6(b) is that the diaphragm 60 in FIG. (6 a) is closed above whilethe one in FIG. 6(b) is shown open. The purpose for showing thisdifference is to illustrate, again, that the diaphragm 60 may be made ina number of ways such as opened above but forming a seal with a coverattached to the valve operating rod or closed above and secured to aninsert 81 which, in turn, can be affixed to the valve operating rod, sothat, in both cases, the valve operating rod can move the assembly,reversibly bringing the sealing tip 62 in contact with the annularsealing surface 21 about the first inlet 20 to open and close the valve.FIGS. 1-5, 6(c), 6(d), 6(e) and 7 all depict some of the many differentarrangements that may be made, all of which include a static seal beingformed between a first, process side of the bottom wall 12 or a raisedsurface of the bottom wall 12 of the internal cavity 11 and a first,process side of the diaphragm 60.

Continuing, the diaphragm 60 in FIG. 6(b) has a short upper shoulder 58supported from beneath by a two-piece insert, the inner piece 171 ofwhich rests against a lip or step 131 formed in the valve operating rod130. The short upper shoulder 58 forms the sealing surface 63 that mateswith the sealing surface 21 about the first inlet 20. The shape of thenested two-piece insert is designed so as to facilitate assembly of asemi-ridged diaphragm 60 onto a supporting insert structure. The outernesting insert 172 which fits into the diaphragm recess can be sectionedvertically into pie sections to facilitate assembly. When the threadedcap 74 is tightened down onto the valve operating rod 130 after thetwo-piece nesting insert is in place, the assembly will tend toself-align while, at the same time, forming an upper process side sealwith the short upper shoulder 58 of the diaphragm 60. The sloping in theshort upper shoulder 68 assures it will drain down and away from thesealing interface with the lip of the threaded cap 74. The seal formedon the underside of the diaphragm 60 with the pedestal 50 is the same asin FIG. 6(a). The diaphragm 60 in 6(b) also includes the rib 182 todampen transfer of the flexing motion of the shoulder 68 of thediaphragm 60 as the valve is actuated as in FIG. 6(a).

FIG. 6(c) combines the short upper shoulder 58 and long lower shoulder68 seen in FIG. 6(b) but without the added rib 182 of FIG. 6(b).Instead, a separate sealing cap 83 is included, similar to that seen inFIG. 4 and 5, but opened at the top as illustrated in FIG. 6(b). Byplacing threads 189 along the inside diameter of the uppermost insert190, a cap 74 can be formed in the end of the valve operating rod 130.With the diaphragm cover in place on the uppermost insert 190, it can bethreaded up on the valve operating rod 130 threads until a tight seal isformed at the top. As in the case of FIG. 6(b) and elsewhere, a drainingseal is achieved. The outer edge of the lower threaded insert 175 isinserted into the recess 191 under the short upper shoulder 58 of thelower flexing diaphragm 60 and a spacer 176 with opposing sealingsurfaces designed to mate with the bottom sealing surface of the sealingcap 83 and the top sealing surface of the bottom flexing diaphragm 60 isplace in position therebetween and the lower threaded insert 175 isthreaded up into the uppermost insert 190. Tightening the lower threadedinsert 175 into the uppermost insert 190 compresses the elements andforms tight seals about the lower shoulder of the sealing cap 83 and theupper shoulder of the lower diaphragm 60. The last seal, formed betweenthe flexing diaphragm and the pedestal 50 and diaphragm clamp sleeve 40is formed in the same fashion and elements as in FIG. 6(b).

One of the benefits of the embodiment of FIG. 6(c) is that thediaphragms and sealing caps used can be designed so they are relativelyflat and open, making them easier and less expensive to make.Furthermore, this figure and FIG. 6(d), besides showing some of the manyarrangements possible, demonstrates that the same diaphragm can be usedto make many different arrangement and configurations. All four of thediaphragm and sealing cap pieces depicted in FIGS. 6(c) and 6(d) areidentical. One practical benefit of such design arrangement is that onlyone type of replacement part needs to be stocked.

As mentioned above, the diaphragm and sealing cap elements pictured inFIG. 6(d) are identical to each other as well as to each of the onespictured in FIG. 6(c). In order to form the seals for the sealing cap83, a set of inserts 177 and 178 with mating sealing faces and withthreaded inside diameters are introduced. These may be threaded up ontothe threads on the outside of the valve operating rod 130 and made tosecurely engage and form seals with the sealing faces of the sealingcap. The upper seal of the lower diaphragm 60 is formed with the bottomof the second insert 178 and the top of a third insert 176, alsothreaded up on the valve operating rod 130 on its inside diameterthreads. The lower seal of the diaphragm 60, the diaphragm which will beperform the flexing in this case, is formed with the same structuralelements and in the same manner as was the seal in FIG. 1. The thirdinsert 176 provides the same supporting shoulder function as did theshoulder 122 formed as a part of the valve operating rod 130 in FIG. 1.Lastly, this third insert 176 is depicted with two sets of o-ring seals195 and 196 to seal against the inside diameter 41 of the diaphragmclamp sleeve 40 while the counterpart sealing arrangement depicted inFIG. 1 only showed one o-ring seal. It should be understood that onecould, in all instances that appear in the present disclosure, includemore than one o-ring-o-ring groove sealing combination if it were deemeddesirable to do so.

All of the structures in FIG. 6(e) can be found within FIG. 6(c).Essentially, FIG. 6(e) combines both the upper and lower double-layerdiaphragm elements into one diaphragm element. This element is openabove and below, having seal-forming surfaces with lips locatedannularly about each opening. As in FIG. 6(c), once the insert 179 isplaced within the recess of the diaphragm, it can be threaded up ontothe threads near the tip of the valve operating rod. As the insert 179is tightened onto these threads, the center upper annular seal surfacewith its lip are brought into tight contact with the opposinginterlocking sealing surface and lip combination formed on the lowerside of the valve operating rod 130 tip. Because the seal is formed withall the elements having externally declining surfaces, this sealingarrangement, used here and depicted in other figures, such as in FIGS.6(c) and 6(d), drains and does not collect material. This sealingarrangement is the same as in 6(b) but it is depicted formed out furtheron the upper shoulder and, instead of the insert being threaded up onthe valve operating rod 130, the tip is a separate piece with threadsand is tightened down from above on the valve operating rod 130. Themanner in which the lower shoulder seal is formed with the pedestal 50and the diaphragm clamp sleeve 40 in 6(e) is the same as in all of theother configurations pictured here. FIG. 6(e) also depicts a diaphragm60 with a rib 182 formed in a recess 181 in the insert 179. What makesthis diaphragm arrangement special is its compactness and the fact thatit would lend itself to manufacturing with the insert 179 in place,particularly if the application allowed the diaphragm to be manufacturedwithout the lips which are needed sometimes to help assure the stabilityof the seal.

FIG. 7 illustrates a diaphragm tulip valve. Tulip or kettle valvesavailable today still include a dynamic O-ring seal placed at the bottomof the internal valve cavity, behind a first surface of the bottom wallof that cavity as they have for years. This design approach, althoughsimple, mechanically dependable and inexpensive to manufacture, resultsin the formation of a collection well or sump just above the dynamicO-ring seal formed with the valve operating rod or stem, and is a sitewhere material collects and adheres and, later, between process batches,becomes very difficult to remove in-situ without manual intervention.Concerns about batch-to-batch contamination are further enhanced withdesign by the fact that material can be carried down past the O-ringseal where it will be sheltered from cleaning and sterilizing proceduresonly to be reintroduced some time later, resulting in contamination ofthat batch. In spite of these problems, tulip or kettle valves are stillused quite widely today in processes that are robust and resistant tothe effects associated with carryover contamination, such as in manyfood, beverage and toiletry products as well as in chemicalmanufacturing. They are usually not found in pharmaceuticalmanufacturing or other industries where aseptic processing is beingcarried out because of major concerns about contamination risksassociated with the difficulty of seal in-situ cleaning andresterilizing.

By applying the novel seal design approach discussed earlier in both thediaphragm and O-ring configurations, depending on the specific processneeds of the user, the problems associated with tulip or kettle valvescan be largely overcome, allowing these very cost effective designs tobe used in a greater number of more demanding aseptic processingapplications as well as providing better, more reliable service incurrent applications.

In the particular case of applying inverted seal diaphragm technology, apedestal 50 is extended up from the first side of the bottom wall 12through the first inlet 20 and the lip 71 on the inner diameter of theflexing diaphragm 60 is captured by inserting the diaphragm clampingsleeve 40 through the center hole 72 in diaphragm 60 and then insertingit into the central bore 51 of pedestal 50. As described previously, theinner diameter (which may or may not have a lip 71) of the diaphragm 60is captured between the shoulder 43 of the diaphragm clamping sleeve 40and the top annular surface 53 of pedestal 50 as retainer nut 140(FIG. 1) or other tightening devices are applied at the distal end ofthe diaphragm clamping sleeve 40. If the seal had the diaphragm formedas an integrated part, then, by definition the outer diameter lip of thediaphragm would be an integrated part of the sealing tip and it wouldnot be necessary to further secure it to the sealing tip. If, however,the diaphragm is not formed as an integrated part of the sealing tip, itwould need to be captured on the sealing tip as well as illustrated inFIG. 7. Accordingly, in FIG. 7, a threaded collar insert 73 is formed asa part of the diaphragm 60 or is inserted into a mating space within thediaphragm 60 near its outer rim. The further radially this threadedcollar can be installed allows greater flexing diaphragm cone radiusesto be used, thus, allowing greater ranges of motion to be achieved. Withthe end of valve operating rod 130 partially inserted into the centralbore 41 of diaphragm clamping sleeve 40, the mating threads 76 of cap 74affixed on the end of valve operating rod 130 can be mated and tightenedonto the threads 75 of collar insert 73. As these threads are tightened,and outer annular surface 77 of the diaphragm 60 is brought into sealingcontact with an opposing sealing surface 78 on cap 74, thereby creatingan outer seal, which, in combination with the inner seal, seals off andisolates the process from the internal mechanical elements of valve andthe surrounding outside environment. In so doing, a seal arrangement iscreated in a tulip or kettle valve, resulting in a valve with all of thebenefits of tulip or kettle valves and the additional benefit of nowbeing a sanitary diaphragm design which can effectively be cleaned andsterilized in-situ and which would now be acceptable for use in asepticprocessing applications as well as in all of the traditionalapplications it has been used for in the past.

It should be noted that the all of the above-described diaphragmarrangements in FIGS. 6(a)-6(c) and 6(e) may be constructed to seal fromabove the surface 102 as in FIG. 7. This would provide the sameadvantages to tulip valve constructions mentioned above, whileadditionally isolating the process from valve elements and thesurrounding outside environment.

FIG. 8 is an O-ring seal tulip valve. In the food and beverage industry,many operators continue to used the traditional O-ring-based tulip andkettle valve designs, as described above, because they are, relativelyspeaking, very inexpensive to install and maintain. Furthermore, formost food and beverage applications where the process is fairly robustand resistant to contamination episodes, the traditional valve designshave provided long periods of service with minimal down time formaintenance. Nonetheless, there have been several incidents in the lastfew years where these types of valves have been implicated as the sourceof food and beverage contamination episodes that resulted in seriousillness to people. Because these valves are frequently used in processapplications that do not lend themselves to the introduction ofdiaphragm valves, either for physical, chemical or economic reasons, itis still of value to try to improve upon their design so as to furtherreduce the risk of process contamination events in the future.

FIG. 8 is an example illustrating how tulip and kettle valves can bemodified and their sealing systems rearranged using inverted sealtechnology to make them easier to clean and sterilize in-situ, to reducetheir threat as a potential source of process contaminants, includingthreatening microbes. The valve body 10 has a pedestal 50 extending upfrom the bottom wall 12 of the internal valve cavity 11. Valve operatingrod 130 is fitted with or is formed with a cap 74 as in FIG. 7. The capmay itself be capable of forming a seal with the inlet annular sealingsurface 21 about the first inlet 20 or it may have integrated into it asealing element (not shown) or the sealing surface 21 with which it willmate may have a sealing element 23 integrated therewith, as can be seenin FIG. 8. In any case, a seal may be reversibly formed with a matingannular sealing surface 84 about the first inlet 20 on either the uppersurface 102 or the lower surface or roof 13 of the cover plate 100 aboutfirst inlet 20. In the example illustrated in FIG. 8, the valveoperating rod would extend through first inlet 20 and the affixed cap 74would be raised above the first inlet 20 in the opened condition and beretracted so as to bring the sealing surface 84 of the cap 74, in thisinstance located on its lower margin, into sealing contact with an upperannular sealing surface 21 located along surface 102 of cover plate 100and sealing element 23 into sealing contact with each other. In thesecond case (see FIG. 9), where cap 74 is positioned within the internalcavity 11 of the valve 1, extending the valve operating rod 130 wouldbring the sealing surface 84, now located on an upper margin of the cap74, into sealing contact with annular sealing surface 21 located on roof13 and sealing element 23 about first inlet 20. In both cases (FIG. 8and FIG. 9), a seal sleeve 80 coaxial with the valve operating rod 130extends down from the bottom of cap 74 formed or affixed on the end ofvalve operating rod 130 and mates, along its inside diameter wall 79,with an outside diameter wall 54 of pedestal 50. An O-ring groove 91 iscut into the inside diameter wall 79 of seal sleeve 80 just above alower margin 92 thereof. An O-ring 93 installed in O-ring groove 91forms a sliding sealing arrangement with the outside diameter wall 54 ofpedestal 50. The benefits of this sealing device is that it is invertedfrom that found in traditional tulip, kettle, plug, ball and other valvedesigns, thereby creating a passively draining sealing arrangement thatwill not tend to collect material in pooling fashion as is found withthe prior art. Additionally, an access to the non-process side of theseal can be achieved by boring holes in the valve operating rod asillustrated in FIG. 7 or, as illustrated in FIGS. 8 and 9, byconstructing an upper portion XXX of pedestal 50 with an inside diameterlarger than an outside diameter of valve operating rod 130, asignificantly sized space 55 may be created within the pedestal.Referring to FIGS. 8 and 9, feed and drain passages 14 and 15 can bebored in bottom wall 12 of valve body 10 that will be large enough forcleaning agents, rinses and steam can be fed at high flow rates into thecavity to assure highly effective in-situ cleaning, rinsing andsterilizing of the non-process side of sliding sealing arrangement to beaccomplished without clogging. The process side of the valve can becleaned by including a second inlet opening directly into the valve bodyinternal cavity 11, as illustrated in FIGS. 1 and 2, through whichcleaning agents, rinses and steam directly can be supplied. These willbe drained from the valve internal cavity by flowing down and out thedrain outlet 30. This design has the special benefit of a seal designthat can be very effectively cleaned from both the process andno-process sides simultaneously. Because it is best to clean andsterilize an O-ring seal when the mating surfaces are exposed andaccessible to the cleaning, rinsing and sterilizing agents, the valveillustrated in FIG. 8 and described above could most effectively becleaned and sterilized when it is in the open (extended) position. Thevalve illustrated in FIG. 9 and also described above, could best becleaned while in the closed position.

It should be noted that, once the concept of inverted seal technology isunderstood, many other variations on the concept will become apparent tosomeone knowledgeable in the art.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. A valve for draining a process from a tank orconduit, comprising: a valve body; a first inlet formed in said valvebody; an outlet formed in said valve body; an internal cavity formed insaid valve body and in communication with said first inlet and saidoutlet, said internal cavity being at least partly defined by a bottomwall having a first side facing the process and a second side facingaway from the process; a sealing tip, said sealing tip having a firstside facing the process and a second side facing away from the process;a valve operating rod, said valve operating rod being connected to saidsealing tip and movable to move said sealing tip into sealing contactwith an annular surface about said first inlet into said internal cavityto form a first seal for sealing the internal cavity from communicationwith the process; a second seal, said second seal being a dynamic sealand being formed between said first side of said bottom wall of saidinternal cavity and said second side of said sealing tip to isolate saidvalve operating rod and the surrounding outside environment from theprocess.
 2. The valve according to claim 1, wherein said bottom wall ofsaid internal cavity includes a hole therethrough for receiving saidvalve operating rod, said bottom wall including a first portion aroundsaid hole being raised with respect to a second portion of said bottomwall immediately adjacent thereto, said first portion forming said firstand second sides of said bottom wall and being sealed by said seal. 3.The valve according to claim 2, wherein said raised portion is acylindrical portion having an outside diameter forming said first sideof said bottom wall, and said sealing tip includes a sealing sleevehaving an inside diameter for forming said second side of said sealingtip and for sliding on said outside diameter of said cylindricalportion, said second seal being located between said sealing sleeve andsaid cylindrical portion.
 4. The valve according to claim 1, wherein abottom most surface of said bottom wall has a continuously decliningpath toward said outlet to promote the drainage of the process out ofsaid internal cavity.